This invention relates to a process and an apparatus for the production of food products by coextrusion cooking.
More particularly, the present invention relates to the production of food products by coextrusion cooking in which one or more cooked coextruded strands(s) is/are subsequently cut up to give products of predetermined shape.
U.S. Pat. No. 3,480,445, for example, relates to a process and an apparatus for the production of a coextruded product in which an outer envelope based on cereals is extruded under pressure with a small addition of water. During this operation, the water is evaporated and the envelope is cooked, and after the envelope has emerged from the extrusion die when it is back at atmospheric pressure, the cooked product expands radially. At the same time, a filling inside the cereal envelope, for example consisting of dairy products or fruits, is coextruded.
The end product obtained is finally cooled and then cut into pieces.
European Patent Application Publication No. 178 878, for example, relates to an apparatus for cutting a strand consisting of an outer envelope of dough and an inner filling.
According to this document, a conveyor belt transports the strand, at least one cutter being arranged above the conveyor belt. The cutter makes an alternating up-and-down movement combined with a longitudinal movement in the direction of advance of the product to be cut.
On the one hand, however, this document does not relate to a cooked product and, on the other hand, only enables a strand to be cut perpendicularly to its axis.
Now, coextruded cooked products cannot be compared with products obtained by simple coextrusion which then have to be cooked to give a finished food product.
This is because uncooked products are highly deformable. Thus, the compression of the filling by which cutting is inevitably accompanied merely causes stretching of the outer envelope which enables the compressed filling to assume the necessary position.
By contrast, products obtained by coextrusion cooking are cooked and lead directly after cutting to a finished product.
Thus, the plastic character of the product obtained after coextrusion cooking is very limited, and compression of the filling caused by a cutter cannot be totally compensated for by stretching of the envelope, which can only be minimal.
In addition, the prior art does not enable products of any shape to be obtained from a coextruded strand, the cross-section of the coextruded strand being constant in shape.
Accordingly, the object of the present invention is to solve these problems.